components/TopSites/_TopSites.scss

$top-sites-size: $grid-unit;
$top-sites-border-radius: 4px;
$top-sites-title-height: 30px;
$top-sites-vertical-space: 8px;
$screenshot-size: cover;
$rich-icon-size: 96px;
$default-icon-wrapper-size: 42px;
$default-icon-size: 32px;
$default-icon-offset: 6px;
$half-base-gutter: $base-gutter / 2;
$hover-transition-duration: 150ms;

.top-sites {
  // Take back the margin from the bottom row of vertical spacing as well as the
  // extra whitespace below the title text as it's vertically centered.
  margin-bottom: $section-spacing - ($top-sites-vertical-space + $top-sites-title-height / 3);
}

.top-sites-list {
  list-style: none;
  margin: 0 (-$half-base-gutter);
  padding: 0;

  // Two columns
  @media (max-width: $break-point-medium) {
    > :nth-child(2n+1) {
      @include context-menu-open-middle;
    }

    > :nth-child(2n) {
      @include context-menu-open-left;
    }
  }

  // Four columns
  @media (min-width: $break-point-medium) and (max-width: $break-point-large) {
    :nth-child(4n) {
      @include context-menu-open-left;
    }
  }
  @media (min-width: $break-point-medium) and (max-width: $break-point-medium + $card-width) {
    :nth-child(4n+3) {
      @include context-menu-open-left;
    }
  }

  // Six columns
  @media (min-width: $break-point-large) and (max-width: $break-point-large + 2 * $card-width) {
    :nth-child(6n) {
      @include context-menu-open-left;
    }
  }
  @media (min-width: $break-point-large) and (max-width: $break-point-large + $card-width) {
    :nth-child(6n+5) {
      @include context-menu-open-left;
    }
  }

  // Eight columns
  @media (min-width: $break-point-widest) and (max-width: $break-point-widest + 2 * $card-width) {
    :nth-child(8n) {
      @include context-menu-open-left;
    }
  }
  @media (min-width: $break-point-widest) and (max-width: $break-point-widest + $card-width) {
    :nth-child(8n+7) {
      @include context-menu-open-left;
    }
  }

  .hide-for-narrow {
    display: none;
  }

  @media (min-width: $break-point-medium) {
    .hide-for-narrow {
      display: inline-block;
    }
  }

  @media (min-width: $break-point-large) {
    .hide-for-narrow {
      display: none;
    }
  }

  @media (min-width: $break-point-widest) {
    .hide-for-narrow {
      display: inline-block;
    }
  }

  li {
    margin: 0 0 $top-sites-vertical-space;
  }

  &:not(.dnd-active) {
    .top-site-outer:-moz-any(.active, :focus, :hover) {
      .tile {
        @include fade-in;
      }

      @include context-menu-button-hover;
    }
  }
}

// container for drop zone
.top-site-outer {
  padding: 0 $half-base-gutter;
  display: inline-block;

  // container for context menu
  .top-site-inner {
    position: relative;

    > a {
      color: inherit;
      display: block;
      outline: none;

      &:-moz-any(.active, :focus) {
        .tile {
          @include fade-in;
        }
      }
    }
  }

  @include context-menu-button;

  .tile { // sass-lint:disable-block property-sort-order
    border-radius: $top-sites-border-radius;
    box-shadow: inset $inner-box-shadow, var(--newtab-card-shadow);
    cursor: pointer;
    height: $top-sites-size;
    position: relative;
    width: $top-sites-size;

    // For letter fallback
    align-items: center;
    color: var(--newtab-text-secondary-color);
    display: flex;
    font-size: 32px;
    font-weight: 200;
    justify-content: center;
    text-transform: uppercase; // sass-lint:disable-line no-disallowed-properties
    transition: box-shadow $hover-transition-duration;

    &::before {
      content: attr(data-fallback);
    }
  }

  .screenshot {
    background-color: $white;
    background-position: top left;
    background-size: $screenshot-size;
    border-radius: $top-sites-border-radius;
    box-shadow: inset $inner-box-shadow;
    height: 100%;
    left: 0;
    opacity: 0;
    position: absolute;
    top: 0;
    transition: opacity 1s;
    width: 100%;

    &.active {
      opacity: 1;
    }
  }

  // Some common styles for all icons (rich and default) in top sites
  .top-site-icon {
    background-color: var(--newtab-topsites-background-color);
    background-position: center center;
    background-repeat: no-repeat;
    border-radius: $top-sites-border-radius;
    box-shadow: var(--newtab-topsites-icon-shadow);
    position: absolute;
  }

  .rich-icon {
    background-size: cover;
    height: 100%;
    inset-inline-start: 0;
    top: 0;
    width: 100%;
  }

  .default-icon,
  .search-topsite {
    background-size: $default-icon-size;
    bottom: -$default-icon-offset;
    height: $default-icon-wrapper-size;
    inset-inline-end: -$default-icon-offset;
    width: $default-icon-wrapper-size;

    // for corner letter fallback
    align-items: center;
    display: flex;
    font-size: 20px;
    justify-content: center;

    &[data-fallback]::before {
      content: attr(data-fallback);
    }
  }

  .search-topsite {
    background-image: url('#{$image-path}glyph-search-16.svg');
    background-size: 26px;
    background-color: $blue-60;
    border-radius: $default-icon-wrapper-size;
    -moz-context-properties: fill;
    fill: $white;
    box-shadow: var(--newtab-card-shadow);
    transition-duration: $hover-transition-duration;
    transition-property: background-size, bottom, inset-inline-end, height, width;
  }

  &:hover .search-topsite {
    $hover-icon-wrapper-size: $default-icon-wrapper-size + 4;
    $hover-icon-offset: -$default-icon-offset - 3;

    background-size: 28px;
    border-radius: $hover-icon-wrapper-size;
    bottom: $hover-icon-offset;
    height: $hover-icon-wrapper-size;
    inset-inline-end: $hover-icon-offset;
    width: $hover-icon-wrapper-size;
  }

  // We want all search shortcuts to have a white background in case they have transparency.
  &.search-shortcut {
    .rich-icon {
      background-color: $white;
    }
  }

  .title {
    color: var(--newtab-topsites-label-color);
    font: message-box;
    height: $top-sites-title-height;
    line-height: $top-sites-title-height;
    text-align: center;
    width: $top-sites-size;
    position: relative;

    .icon {
      fill: var(--newtab-icon-tertiary-color);
      inset-inline-start: 0;
      position: absolute;
      top: 10px;
    }

    span {
      height: $top-sites-title-height;
      display: block;
      overflow: hidden;
      text-overflow: ellipsis;
      white-space: nowrap;
    }

    &.pinned {
      span {
        padding: 0 13px;
      }
    }
  }

  .edit-button {
    background-image: url('#{$image-path}glyph-edit-16.svg');
  }

  &.placeholder {
    .tile {
      box-shadow: inset $inner-box-shadow;
    }

    .screenshot {
      display: none;
    }
  }

  &.dragged {
    .tile {
      background: $grey-20;
      box-shadow: none;

      *,
      &::before {
        display: none;
      }
    }

    .title {
      visibility: hidden;
    }
  }
}

.edit-topsites-wrapper {
  .modal {
    box-shadow: $shadow-secondary;
    left: 0;
    margin: 0 auto;
    max-height: calc(100% - 40px);
    position: fixed;
    right: 0;
    top: 40px;
    width: $wrapper-default-width;

    @media (min-width: $break-point-medium) {
      width: $wrapper-max-width-medium;
    }

    @media (min-width: $break-point-large) {
      width: $wrapper-max-width-large;
    }
  }
}

.topsite-form {
  $form-width: 300px;
  $form-spacing: 32px;

  .section-title {
    font-size: 16px;
    margin: 0 0 16px;
  }

  .form-input-container {
    max-width: $form-width + 3 * $form-spacing + $rich-icon-size;
    margin: 0 auto;
    padding: $form-spacing;

    .top-site-outer {
      pointer-events: none;
    }
  }

  .search-shortcuts-container {
    max-width: 700px;
    margin: 0 auto;
    padding: $form-spacing;

    > div {
      margin-inline-end: -39px;
    }

    .top-site-outer {
      margin-inline-start: 0;
      margin-inline-end: 39px;
    }
  }

  .top-site-outer {
    padding: 0;
    margin: 24px 0 0;
    margin-inline-start: $form-spacing;
  }

  .fields-and-preview {
    display: flex;
  }

  label {
    font-size: $section-title-font-size;
  }

  .form-wrapper {
    width: 100%;

    .field {
      position: relative;

      .icon-clear-input {
        position: absolute;
        transform: translateY(-50%);
        top: 50%;
        inset-inline-end: 8px;
      }
    }

    .url {
      input:dir(ltr) {
        padding-right: 32px;
      }

      input:dir(rtl) {
        padding-left: 32px;

        &:not(:placeholder-shown) {
          direction: ltr;
          text-align: right;
        }
      }
    }

    .enable-custom-image-input {
      display: inline-block;
      font-size: 13px;
      margin-top: 4px;
      cursor: pointer;
    }

    .custom-image-input-container {
      margin-top: 4px;

      .loading-container {
        width: 16px;
        height: 16px;
        overflow: hidden;
        position: absolute;
        transform: translateY(-50%);
        top: 50%;
        inset-inline-end: 8px;
      }

      // This animation is derived from Firefox's tab loading animation
      // See https://searchfox.org/mozilla-central/rev/b29daa46443b30612415c35be0a3c9c13b9dc5f6/browser/themes/shared/tabs.inc.css#208-216
      .loading-animation {
        @keyframes tab-throbber-animation {
          100% { transform: translateX(-960px); }
        }

        @keyframes tab-throbber-animation-rtl {
          100% { transform: translateX(960px); }
        }

        width: 960px;
        height: 16px;
        -moz-context-properties: fill;
        fill: $blue-50;
        background-image: url('chrome://browser/skin/tabbrowser/loading.svg');
        animation: tab-throbber-animation 1.05s steps(60) infinite;

        &:dir(rtl) {
          animation-name: tab-throbber-animation-rtl;
        }
      }
    }

    input {
      &[type='text'] {
        background-color: var(--newtab-textbox-background-color);
        border: $input-border;
        margin: 8px 0;
        padding: 0 8px;
        height: 32px;
        width: 100%;
        font-size: 15px;

        &:focus {
          border: $input-border-active;
          box-shadow: var(--newtab-textbox-focus-boxshadow);
        }

        &[disabled] {
          border: $input-border;
          box-shadow: none;
          opacity: 0.4;
        }
      }
    }

    .invalid {
      input {
        &[type='text'] {
          border: $input-error-border;
          box-shadow: $input-error-boxshadow;
        }
      }
    }

    .error-tooltip {
      animation: fade-up-tt 450ms;
      background: $red-60;
      border-radius: 2px;
      color: $white;
      inset-inline-start: 3px;
      padding: 5px 12px;
      position: absolute;
      top: 44px;
      z-index: 1;

      // tooltip caret
      &::before {
        background: $red-60;
        bottom: -8px;
        content: '.';
        height: 16px;
        inset-inline-start: 12px;
        position: absolute;
        text-indent: -999px;
        top: -7px;
        transform: rotate(45deg);
        white-space: nowrap;
        width: 16px;
        z-index: -1;
      }
    }
  }

  .actions {
    justify-content: flex-end;

    button {
      margin-inline-start: 10px;
      margin-inline-end: 0;
    }
  }

  @media (max-width: $break-point-medium) {
    .fields-and-preview {
      flex-direction: column;

      .top-site-outer {
        margin-inline-start: 0;
      }
    }
  }

  // prevent text selection of keyword label when clicking to select
  .title {
    -moz-user-select: none;
  }

  // CSS styled checkbox
  [type='checkbox']:not(:checked),
  [type='checkbox']:checked {
    inset-inline-start: -9999px;
    position: absolute;
  }

  [type='checkbox']:not(:checked) + label,
  [type='checkbox']:checked + label {
    cursor: pointer;
    display: block;
    position: relative;
  }

  $checkbox-offset: -8px;

  [type='checkbox']:not(:checked) + label::before,
  [type='checkbox']:checked + label::before {
    background: var(--newtab-background-color);
    border: $input-border;
    border-radius: $border-radius;
    content: '';
    height: 21px;
    left: $checkbox-offset;
    position: absolute;
    top: $checkbox-offset;
    width: 21px;
    z-index: 1;

    [dir='rtl'] & {
      left: auto;
      right: $checkbox-offset;
    }
  }

  // checkmark
  [type='checkbox']:not(:checked) + label::after,
  [type='checkbox']:checked + label::after {
    background: url('chrome://global/skin/icons/check.svg') no-repeat center center; // sass-lint:disable-line no-url-domains
    content: '';
    height: 21px;
    left: $checkbox-offset;
    position: absolute;
    top: $checkbox-offset;
    width: 21px;
    -moz-context-properties: fill;
    fill: var(--newtab-link-primary-color);
    z-index: 2;

    [dir='rtl'] & {
      left: auto;
      right: $checkbox-offset;
    }
  }

  // when selected, highlight the tile
  [type='checkbox']:checked + label {
    .tile {
      box-shadow: 0 0 0 2px var(--newtab-link-primary-color);
    }
  }

  // checkmark changes
  [type='checkbox']:not(:checked) + label::after {
    opacity: 0;
  }

  [type='checkbox']:checked + label::after {
    opacity: 1;
  }

  // accessibility
  [type='checkbox']:checked:focus + label::before,
  [type='checkbox']:not(:checked):focus + label::before {
    border: 1px dotted var(--newtab-link-primary-color);
  }
}

//used for tooltips below form element
@keyframes fade-up-tt {
  0% {
    opacity: 0;
    transform: translateY(15px);
  }

  100% {
    opacity: 1;
    transform: translateY(0);
  }
}